Hitherto, a droplet amount ejected from a nozzle of an inkjet head used in an inkjet recording apparatus has a variation of ±5 to 10% for each nozzle. Inkjet heads are different from each other in the shape accuracy of nozzles and pressure chambers, and the characteristic accuracy of piezoelectric material and the like.
The variation becomes a density variation of a printed material. Especially, when an inkjet technique is used for printing of a color filter or the like of a liquid crystal display, the accuracy of the inkjet technique dominates the performance of a product.
Hitherto, in an inkjet head having plural nozzles, in order to reduce variation in droplet amounts from the respective nozzles, a method is used in which a drive waveform is changed for each of the nozzles.
However, in order to use this method for the inkjet recording apparatus, a drive circuit is required for each of the nozzles. Thus, the drive circuit to drive the whole inkjet head becomes large and expensive.
The invention provides a density correction system capable of reducing variation in droplet amount per one pixel.